Bundle tying machine



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' BUNDLE TYING MACHINE Filed. March 25, 1954 5 Sheets-Sheet 3 69' INVENTOR.

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BUNDLE TYING MACHINE Filed March 25, 1954 5 Sheets-Sheet 5 ,nvmvron Eeryanzuzfl. 5mm

United States Patent BUNDLE TYING MACHINE Benjamin H. Bunn, Chicago, Ill., assignor to B. H. Bunn Company, Chicago, Ill., a corporation of Illinois Application March 25, 1954, Serial No. 418,587

4 Claims. (Cl. 100-27) This invention relates to machines for tying bundles of material, such as stacked paper envelopes filled with mail or the like.

- Mailhaving one destination is commonly tied to 'gether in a bundle for ease of handling, the tying medium being one or more Wraps of twine, the ends of whichare secured together by a knot. The average letter-size envelope containing a folded letter is thicker over its central region than it is at its ends. In many instances, the letter is so folded as to leave considerable space at the ends of the envelopes. As a result, when a number of envelopes filled with folded letters or material are stacked upon one another, the central regions of the letters may be tightly packed but the ends will be loose, that is, the ends will be capable of compression to a thinner bundle than the mid-portions. Also, envelopes containing mail usually contain a considerable amount of air at both the mid-portion and the ends which can be squeezed out by compression to compact the stack.

An important object of this invention is the provision of an improved tying machine for tying bundles of envelopes containing mail or the like wherein means are: provided for compensating for the difference in thickness between the central and outer regions of the envelopes. The knotter used with the average typing machine must necessarily be located as close to the bundle as the ends than at their midportions,- the tension in the twine tends to raise the edge of the envelope away from the knotter because of the relatively uncompacted state of the ends of the envelope, with the result that the knot is not tied close to the bundle and the resulting bundle is somewhat loose.

Another important object of this invention is to pro vide a machine for tying bundles of envelopes containing mail or the like wherein the knotter is moved inwardly from the ends of the bundle and into proximity with the thick, well compacted central region of the letters in order to produce a tight bundle.

The average letter, after it is sealed, contains some air which gives the envelope slightly greater bulk than the material of the envelope and the letter included therein actually possesses.

Another object of this invention, therefore, is the provision of means on the table or platform of a tying machine which must be depressed by the bundle of letters to be tied before the tying operation can commence, the means exerting sufficient resistance to such compression to cause the bundle to be somewhat com pressed by the operator, and a portion of the air squeezed out before the tying operation commences.

. Another object of this invention is the provision of a. table for a tying machine for bundles ofenvelopes containing mail or the like wherein the surface of the table is curved upwardly over the region normally occupied by one of the bundle while it is being tied in' tion will become apparent from the following detailed p-orating this invention;

description when taken together with the accompanying drawings in which:

Fig. 1 is a top plan view of a tying machine incor- Fig. 2 is a side elevational view of the tying machine shown in Fig. l;

Fig. 3 is an enlarged fragmentary rear elevational view, in section, of the machine in Fig. 2' with the section taken substantially along a line 33 of Fig. 2;

' Fig. 4 is a still further enlarged fragmentary rear elevational view, in section, of the machine of Fig. 2, the section corresponding to a portion of 'the section shown in Fig. 3, and showing the machine in another stage of its operation;

Fig. 5 is a fragmentary side elevational view of the the machine, and

Figs. 9 and 10 are bottom views in perspective of bundles which have been-tied in one direction andin two directions, respectively, by a machine incorporating this invention.

The general organization of the tying machine depicted in the accompanying drawings is similar to that of the machine disclosed and claimed in my co-pending application Serial No. 383,066, filed September 29, 1953, and 'the details of the knotter and its mode of operation are described in my prior Patent No. 1,606,290, dated November 9, 1926. The description herein will therefore be confined to the improvements which I have made over the aforesaid prior constructions except insofar as it is necessary to refer to them tov give a complete under-' standing of the entire mechanism which affords the environment for this invention.

Referring first to Figs. 1 and 2, the tying machine clutch 28 to a drive shaft 29 which is rotatably supported by frame 20 with its axis substantially parallel to the axis of motor drive pulley 25. A pinion gear 30 secured to and driven by shaft 29 meshes with a large driven gear 31 disposed on a drum 32 adjacent an interrupted gear 33. A gear 34 is adapted to mesh with interrupted gear 33, said gear 34 driving a sprocket 35 connected by a chain 37 to a small sprocket 36. Said sprocket 36 is secured to and rotates with a hollow shaft 38 supported in a bearing 39 on a frame 20. I

Shaft 38 supports and drives a hollow twine arm 40 having a portion extending in a direction generally parallel to the axis of shaft 38 and connected to said shaft 38 by a radial portion 41.

A container 50 is supported on frame 20 at the lower f regions thereof and holds a spoo'l-of twine 51, thefree end of which passes upward out of container 50 through a guide 49 and then transversely through a tensioning device 48 from which it moves upwardly into the outer or left-hand end of the hollow shaft 38, as viewed in Fig. 2. It emerges therefrom through an opening 47, from which it passes through a guide 46 and rings 45 and 44 disposed on the radial portion 41 of the arm 40 and thence along the arm 40 through an opening 42 in the end thereof to a holding device 52 disposed in proximity to the knot tying mechanism of the machine.

The knot tying mechanism or knotter is shown clearly in Figs. 4 and 5, to which reference is now made, and embodies a bearing member 53 through which a shaft 54 passes, one end of which is secured to a mitre gear 55 meshing with a similar mitre gear 56 supported on a swinging frame 57. The upper end of bearing member 53 has thereona cam surface. 58 on which a roller 59 rides, that roller being secured to the pivoted jaw 60 of the knotter. A jaw 61, fixed relative to the cam 58 is formedon the upper end of shaft 54, and is rotatable therewith. Swinging frame 57 is supported on a shaft 62 mounted on frame 20 The lower endof frame 57, as shown in Fig. 3, is provided with a roller 63 adapted to bear against a face cam shown generally at 64 and driven from a shaft 65 keyed to gear 31.

Mitre gear 56 is mounted on a shaft 66 for rotation therewith, said shaft 66 extending through swinging frame 57 and being driven by a pinion gear 67 through an interrupted gear 68 (Fig. 3) mounted on shaft 65 and rotatable therewith.

Clutch.28 is controlled by the action of shift fork 72 acting against a collar 69 having a groove70 therein in which the bifurcated end 71 of the shift fork 72 rides.

Said shift fork 72 is pivoted at 73 and is so arranged that,

when fork 72 is swung in a clockwise direction, as viewed in Fig. 2, clutch 28 willbe engaged, and when itfis swung. in the opposite direction, clutch 28 will be disengaged. The swinging movements of shift fork '72 are controlled by a portion of face cam 64 in the manner more fully described in my co-pending application, Serial No. 383,066 referred to. above, the details of which are omitted herein for the. sakeofsirnplicity. The effectiveness of cam 64 to rotate fork 72 to clutch engaging or disengaging position is controlled by a rod 74, shown-in Fig. 3, having a pivoted connection 75 to one arm 76 of a bell crank 77, the otherarm 78 of which is hinged to the lower end 79 of a-push rod 80 extending upward frombell crank 77. A spring 81 stretched between a lug 82 on the lower end 79 of push rod 80 and a lug 83 fixed to frame 20 exerts a continuous upward force on push rod 80 and onarm 78 of bell crank 77, the movement ofsaid bell crank 77 being limited, however, by a stop 84 on frame 20 contacted by an extension 85 on bell crank 77.

The upper end of. push rod 80. bears against the under side of a, lever. 86 pivoted at 87 to frame 20, asshown in Fig. 3, the pivot being disposed below the, surface 88 of a. platform 89.011 which a bundle 91 to be tiedis adapted to be placed. The end 90 of lever 86 extends above surface 88) andis adapted to be contacted by bundle- 9 1. which may be made up of stacked letters or the like.

It. is contemplated that the operation ofthe machine described herein will be initiated by the operation of clutch 28 which, in turn, is initiated by depressing end 90of lever 86 to a position substantially level with the surface 88 of platform 89. The location of lever 86 on platform 89 is such that the depression of lever end 90 is effected by placing a bundle 91 on. platform 89in the position. it is to occupy when it is being tiedby the machine. Then end 90. of lever 86 is located. immediately under the-bundle and. can be. operated only by exerting sufiicient pressure on the. bundleto overcome the resistance of spring. 81. During the compression of the bundle- 91, most of the air trapped therein is forced out and a more compact bundle then results.

It'may be: observed from. Figs. land 5 that. platfornr 89 is supported from frame 20 at its mid region by a bracket 92, and that its left-hand region 93, as there viewed, is substantially unsupported. Platform 89 is initially formed with a slight downward curvature from its mid region toward region 93, and with an upwardly bent tab 94 at the corner thereof which is disposed over the knotter. The surface 88 of platform 89 is smoothly rounded at the base portion 95 of tab 94 to conform in general to the curvature of a compacted stack of letters, or the like. This is shown clearly in Fig. 4. The free end of tab 94 bears against a post 96 secured to frame 20. The material from which platform 89 is made is resilient and sufiiciently flexible that the end region 93 may move vertically to accommodate the operation of the knotter as will be hereinafter described.

Adverting to Fig. 4, it may be observed that the location of the axis of shaft 54, and hence the disposition of jaws 60 and 61, is some distance inward, that is, to the right, of tab 94, the location. ofv which corresponds to the left-hand end of the bundle of envelopes. It maybe observed further that the axis of shaft 54 is substantially atthe point where the rounded base 95, meets the relative.- ly straight surface 88 of platform 89. This disposition of the knotter locates the knot at the closest possible point to the bundle and takes into account the fact that the bottom of the bundle is curved upwardly relative to surface 88. The tying of a knot at the post 96 as would ordinarily be done in prior tying machines, would result in locating the knot some distance from the actual surface of the bundle, and in a loose bundle.

As in described more fully in my aforesaid prior patcut, the operation of clutch 28 causes the rotation of intermittent. gear 33 which, when in mesh with gear 34, causes arm 44 to rotate on shaft 38, thereby wrapping the end 43 of the twine around a bundle properly located on platform 89. After the twine has been wrapped around the bundle as many times as is desired, the interrupted gear then discontinues the drive to gear 34,, and arm 40 is held in substantially the position shown in Fig. 2. until the next tying cycle takes place. During the remainder of. the cycle the tying. operation is performed.v

Adverting again to Fig. 5 and to Figs. 6 and 8, the swinging frame 57 will. cause the top of jaw 61 of the knotter to pass through the space shown occupied by the downwardly bent unsupported region 93 of platform 89. Physical contact between the knotter and the underside of platform 89, however, is to be avoided, and hence means are provided for raising region 93 above the top of jaw 61 of the knotter as the latter swings under saidv region 93. The raising means comprises a lever 97, preferably a stamping having bent over tabs 98 on either side thereof which are apertured as at 99 to receive a pivot pin 100 supported on a bracket 101. A spring 102, normally compressed between bracket 101 and the righthand end of lever 97, as viewed. in Fig. 5, urges said lever in acounterclockwise direction and holds isagainst the upper surface of bracket 101, theopposite end 103 of lever 97 is contacted by the upperend of a push rod 104' supported in lugs 105 secured to frame 20 (Fig. 4). The lower end of push rod 104 rests upon the free end of a lever 106 which is pivoted at 107 (Fig. 3) to frame 20, said lever-having an arm 108 extending downwardly to a position for contact with a cam surface 109 disposed peripherally of plate ,cam 64. Thus, as plate cam 64 rotates about its shaft 65, cam surface 109.will strike the lower end of arm 108 ,and rotate lever 106 clockwise as viewed in Fig. 3, thereby raising the left-hand end of the leverand pushingjrod 104 upward; against lever 97. The latter, in turn, bears against thevunder surface of the unsupported region 93 of platform. 89, and raises said region during the interval that the knotter is passing under: it.

Lever 106- is held out of contact with plate cam 64, except during the interval that it is engaged by surface 109,, by an adjustable stop screw-110. threaded in. arm;

106 and resting upon an abutment 114, the position of the screw in arm 106 being fixed by a lock nut 111.

One end 112 (Fig. 8) of lever 97 is provided with a notch 113 in which the twine is held, and functions to strip the twine off the jaws 60 and 61 as a function of the tying of the knot, all as described in greater detail in my prior Patent No. 1,606,290 mentioned above.

In a complete cycle of operation, a bundle of envelopes 91 is placed over platform 89 with substantially onehalf of the bundle extending to the left of the platform, as viewed in Fig. 2, so that only one-half of the bundle is supported by the platform. The bundle is pushed toward post 96, and in the process, the lower left-hand corner of the bundle, as viewed in Figs. 3 and 4, is brought to bear against the rounded base portion 95 of tab 94. Pressure is then exerted upon the top of the bundle to depress end 90 of lever 86. With the bundle substantially in the location shown in Fig. 4, the depression of said lever end 90 initiates the operation of clutch 28 to cause a rotation of shaft 29, gear 30 and gear 31. The latter rotation results in the rotation of the intermittent gear 33, as well as of shaft 65 on which cam 64 is mounted. The sequential operation of gear33 and cam 64 is such as to cause first a rotation of arm 40 around bundle 91 to wrap 5 reach of twine, preferably with two wraps, around the bundle, and then cam 64 causes the knotter to swing into place underneath platform 89, pushrod 104 raising the platform momentarily to permit this operation, and interrupted gear 68 then causes rotation of shaft 66, mitre gears 55 and 56 and the knotter to tie the knot in the manner described in my said prior Patent No. 1,606,290. After the knit is tied, the bundle may be removed from platform 89, or it may be turned around 90 on platform 89 and the cycle repeated to cross tie the bundle, as shown in Fig. 10.

As shown in Figs. 9 and 10, the resulting bundle, whether tied in one direction or in both directions, will be tightly compacted, first, because of the removal of excess air from the bundle by the initial pressure required upon the bundle to trip lever 86 and initiate the tying operation, and, second, because at least one corner of the bundle has been compressed by a curved surface, the curvature of which corresponds to the curvature of the bundle when the corner thereof is properly and completely compressed, so that the knot can be tied while the twine closely follows the contour of the bundle. The location of the knot at some distance removed from the corner permits such close following of the bundle contours by the twine, and the resilience of the platform over the knotter makes possible the movement of the platform out of the way during a critical portion of the knot tying operation without in any way resulting in a loosening of the knot.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention and that the scope of the invention therefore is not to be limited thereto but is to be determined by the following claims.

I claim:

1. In a tying machine for bundles of stacked envelopes and the like which are compressible at their marginal regions, said machine having means for wrapping a reach of twine around the bundle, said bundle being thicker at its center regions than at its ends, and means for tying a knot in the ends of the wrapped twine at a position on the bottom of the bundle disposed inwardly of the end of the bundle and substantially under the thicker region of the bundle; a platform for supporting the bundle while a reach of twine is wrapped therearound said platform being formed at the region adjacent the knot with a contour which substantially follows the contour of the bundle and being flexible at said region, said knot tying means being disposed to pass through a space normally occupied by the flexible region of the platform, and means for raising the flexible region of the platform in timed relation to the movement of the tying means to permit the tying means to pass through said space as aforesaid.

2. A platform for a tying machine as described in claim 1, said flexible region of the platform terminating in an upwardly bent tab which is coextensive with the thickness of a bundle and is disposed to act as an abutment for the bundle while the bundle is being tied.

3. A platform for a tying machine as described in claim .1, said flexible region of the platform terminating in an upwardly bent tab which is coextensive with the thickness of a bundle, and a rigid abutment adjacent the tab and contacted thereby.

4. In amachine for tying bundles of stacked envelopes and the like which are compressible at their end and side marginal regions, the combination comprising a platform to support the bundle during the tying operation, means for wrapping a reach of twine around the bundle, said bundle being thicker at its center regions than at its ends, means for tying a knot in the ends of the wrapped twine at a position on the bottom of the bundle disposed inwardly of the end of the bundle and substantially under the thicker region of the bundle, said platform being formed at the region adjacent the knot with a contour which substantially shapes the contour of the bundle when it is compressed at said region, said platform being flexible at said region, means for raising the platform at said region to permit the operation of the knot-tying means, and means for operating the raising means in timed relation to the operation of the means for tying a knot.

References Cited in the file of this patent UNITED STATES PATENTS 1,201,688 Bunn et a1 Oct. 17, 1916 1,332,648 Turner Mar. 2, 1920 1,606,290 Bunn Nov. 9, 1926 2,358,685 Bunn Sept. 19, 1944 2,366,235 Bunn Jan. 2, 1945 2,614,487 Cheesman Oct. 21, 1952 2,630,750 Eberle Mar. 10, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2 ,-873 ,664 February 17, 1959 Benjamin H. Bunn It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 40, for "typing" read tying column 3 line 14, for "of which is" read of which shaft is column 4, line 56, for "holds is" read holds it column 5, line 32, for knit is tied" read knot is tied Signed and sealed thisloth day of June 1959 (SEAL) Attest:

KARL 1-1. AXLINE v ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

